Genotype and clinical care correlations in craniosynostosis: findings from a cohort of 630 Australian and New Zealand patients.

Craniosynostosis is one of the most common craniofacial disorders encountered in clinical genetics practice, with an overall incidence of 1 in 2,500. Between 30% and 70% of syndromic craniosynostoses are caused by mutations in hotspots in the fibroblast growth factor receptor (FGFR) genes or in the TWIST1 gene with the difference in detection rates likely to be related to different study populations within craniofacial centers. Here we present results from molecular testing of an Australia and New Zealand cohort of 630 individuals with a diagnosis of craniosynostosis. Data were obtained by Sanger sequencing of FGFR1, FGFR2, and FGFR3 hotspot exons and the TWIST1 gene, as well as copy number detection of TWIST1. Of the 630 probands, there were 231 who had one of 80 distinct mutations (36%). Among the 80 mutations, 17 novel sequence variants were detected in three of the four genes screened. In addition to the proband cohort there were 96 individuals who underwent predictive or prenatal testing as part of family studies. Dysmorphic features consistent with the known FGFR1-3/TWIST1-associated syndromes were predictive for mutation detection. We also show a statistically significant association between splice site mutations in FGFR2 and a clinical diagnosis of Pfeiffer syndrome, more severe clinical phenotypes associated with FGFR2 exon 10 versus exon 8 mutations, and more frequent surgical procedures in the presence of a pathogenic mutation. Targeting gene hot spot areas for mutation analysis is a useful strategy to maximize the success of molecular diagnosis for individuals with craniosynostosis.

Specific unresponsiveness to skin allografts in burns.

We have examined the potential to provide long-term or even permanent wound coverage in a mouse model of a 30% total body surface area burn using skin allografts. Treatment of the recipient mouse with rabbit anti-mouse thymocyte serum (ATS) followed by donor bone marrow infusion induces a state of specific unresponsiveness to the skin allograft without the need for chronic immunosuppression. Specifically, a B6AF1 mouse receives a burn on Day -2 relative to grafting, ATS on Day -1, and Day +2, a skin allograft from a C3H/He mouse on Day 0, and infusion of C3H/He donor bone marrow on Day +6. We studied three groups of burned mice: Group I, allograft control (n = 5); Group II, allograft plus ATS (n = 12); and Group III, allograft plus ATS and bone marrow infusion (n = 15). Mean graft survival was compared using a one-way analysis of variance and a Student-Newman-Keuls post hoc test. There was no statistical difference in animal mortality among any of the three groups, and there was no evidence of infectious morbidity. Mean skin allograft survival was as follows: Group I, 9 days; Group II, 29 days; and Group III, 66 days (P less than 0.05 vs Group I and II). Nine animals in Group III had intact hair bearing grafts at 90 days when the study was terminated. This study suggests the potential use of induced specific unresponsiveness to skin allografts for wound coverage in thermal injury without use of chronic immunosuppression. In our animal study this was accomplished without increased mortality or apparent infectious morbidity.

Clinical characteristics of Peutz-Jeghers syndrome in Korean polyposis patients.

Peutz-Jeghers syndrome is an autosomal dominant inherited disorder characterized by hamartomatous polyps in the small bowel and mucocutaneous pigmentation. Patients with Peutz-Jeghers syndrome often present as surgical emergencies with complications of the polyps, such as intussusception, bowel obstruction, and bleeding. Recently an increased risk of malignancies has also been reported. This study was initiated to determine the clinical features of Peutz-Jeghers syndrome in Korean patients, with special attention to the development of malignancies. Thirty patients with Peutz-Jeghers syndrome were investigated; their median age was 23.5 years, and symptoms appeared at a median age of 12.5 years. Family history was positive in one-half of cases, and mucocutaneous pigmentation was observed in almost all patients (93%). The jejunoileum was the most frequent site of the polyps, and there were generally 10-100 polyps. Multiple laparotomies were performed in a substantial portion of the patients, due mainly to polyp-induced bowel obstruction, and the surgical interventions were begun at a relatively young age (average 21.4 years). Four cases of small-bowel cancer and one case of breast cancer were detected in probands, at a relatively young age (mean 36 years). Cancers of the small bowel, stomach, colon, breast and cervix were diagnosed in the first relatives of the probands. Close follow-up from an early age should thus be performed in patients with Peutz-Jeghers syndrome as they are at high risk of surgical emergency and development of malignancy.